1. Field of the Invention
The present invention relates to an automatic preparation apparatus for automatically preparing samples and a filter therefor. The apparatus automatically performs the preparations such as filtration, dilution, reaction of suspensions and solutions containing chemical substances.
2. Description of the Related Art
When a sample is injected in the component analysis, suspended matter contained within the sample are usually previously removed to dilute it to a predetermined concentration. A centrifugal separator or filter is used for removing the suspended matter from the sample while a measuring pipette is used for diluting the sample. For example, when a (high speed) liquid chromatography system is used to perform the component analysis, neither of the above-mentioned removing and diluting means can directly be coupled with the liquid chromatography system for operational reasons and thus the prepared sample is set to an automatic sampler or is injected into an injector by means of a microsyringe.
Consequently, a liquid chromatography system cannot be run fully automatically including regulation to analysis of the sample and those treatments of the sample are currently being manually carried out.
However, if the preparations are to be manually carried out, a vast amount of treatment time can be required, not to say of the possible occurrence of the treatment error and contamination of the sample. Besides, a problem exits that the preparation and component analysis by the liquid chromatography system cannot automatically be controlled in an interlocking relationship. Furthermore, when the sample is to be filtered by means of the preparing apparatus of this kind, filtration speed of the sample can thereby by retarded or pores of the filter medium can be clogged depending on the kind or size of the inclusions existing within this sample such as bacteria, fiber, fine particles or the like. In such cases, for ease and effective control of the filtration, it is necessary to simultaneously use the proper filter or filter aid.
However, in the case of the currently commercially available or proposed disposable molded filters, since the inner diameter of a portion into which the sample to be filtered may be injected ranges about below 4 to 5 mm, it is difficult to use, as the occasion demands, the other filter, filter as described above, which in turn resulted in slow filtration speed of the sample and a large amount of time required for obtaining enough filtrate to analyze.